Expandable trolley suitcase

ABSTRACT

Expandable trolley suitcase comprising a bottom container having a top opening, and a top container having a bottom opening, the top container and the bottom container being slidably coupled to each other in correspondence of the bottom opening of the first one and of the top opening of the second one, at least one locking device interacting with the bottom container and with the top container and configured to assume a release configuration, at which it allows a reciprocal sliding of the bottom container and top container, and a lock configuration, at which it prevents the reciprocal sliding of the bottom container and top container, thereby the expandable trolley suitcase is configured to assume at least two geometric configurations, at which said at least one locking device assumes the lock configuration, depending on a position assumed by one between the bottom container and the top container with respect to the other, each one of said at least two geometric configurations having a respective storage volume delimited by the bottom container and top container, said at least two geometric configurations including a minimum geometric configuration having a minimum storage volume and a maximum geometric configuration having a maximum storage volume.

The present invention relates to an expandable trolley suitcase that allows a user to easily, reliably and comfortably adjust the size of the trolley suitcase, adapting to different travel needs, the trolley suitcase being capable to be inexpensively made and being durable over time.

It is known that suitcases, in particular trolley suitcases, have different standardized dimensions depending on the stowage characteristics of different means of transport and/or on the stowage requirements imposed by different transport companies, e.g. requirements imposed by airlines for cabin baggage. This entails that, when a user makes multiple trips with different means of transport and/or different transport companies, he/she may need to change the trolley suitcase from one trip to another one to comply with the specific stowage characteristics and/or actual needs of volume of the internal storage space of the trolley suitcase.

In the prior art, some expandable suitcases have been proposed, such as those disclosed in documents CH87118A, GB1208113A, EP2289365A1 and KR101929680B1.

However, these prior art expandable suitcases have a rather complex structure, are neither easy nor comfortable to use, and are often unreliable.

It is an object of this invention, therefore, to allow a user to easily, reliably and comfortably adjust the size of a trolley suitcase, that can be inexpensively made and is also durable over time.

It is specific subject-matter of the present invention an expandable trolley suitcase comprising a bottom container having a top opening, and a top container having a bottom opening, the top container and the bottom container being slidably coupled to each other in correspondence of the bottom opening of the first one and of the top opening of the second one, at least one locking device interacting with the bottom container and with the top container and configured to assume a release configuration, at which it allows a reciprocal sliding of the bottom container and top container, and a lock configuration, at which it prevents the reciprocal sliding of the bottom container and top container, thereby the expandable trolley suitcase is configured to assume at least two geometric configurations, at which said at least one locking device assumes the lock configuration, depending on a position assumed by one between the bottom container and the top container with respect to the other, each one of said at least two geometric configurations having a respective storage volume delimited by the bottom container and top container, said at least two geometric configurations including a minimum geometric configuration having a minimum storage volume and a maximum geometric configuration having a maximum storage volume.

According to another aspect of the invention, the top container and the bottom container may be slidably coupled to each other through a plurality of linear telescopic guides, optionally with aluminium balls.

According to an additional aspect of the invention, said plurality of linear telescopic guides may consist of four linear telescopic guides.

According to a further aspect of the invention, the top container may be configured to slide inside the bottom container.

According to an additional aspect of the invention, the bottom container may comprise a front shell and a rear shell, each one made of a rigid material and having a bottom edge and two lateral edges, which are hinged to each other on a first lateral edge and which are closable by a zipper running along the bottom edge and the second lateral edge of the shells of the bottom container, and the top container may comprise a front shell and a rear shell, each one made of a rigid material and having a bottom edge and two lateral edges, which are closable by a zipper running along the bottom edge and the lateral edges of the shells of the top container.

According to another aspect of the invention, the expandable trolley suitcase may comprise one or more sealing gaskets interposed between the front shells and between the rear shells which are configured to maintain a seal between the bottom container and the top container.

According to a further aspect of the invention, the front shell of the top container may be provided with two or more front linear grooves, the number of which is ranging from the number of said at least two geometric configurations to the number of said at least two geometric configurations increased by two, facing corresponding two or more rear linear grooves, the number of which is equal to the number of said two or more front linear grooves, with which the rear shell of the top container is provided, wherein said two or more front linear grooves and said two or more rear linear grooves are oriented in direction orthogonal a direction of extraction of the top container from the bottom container, each one of said two or more front linear grooves and of said two or more rear linear grooves having a respective central circular recess, wherein said at least one locking device consists of a front locking device interacting with the front shell of the bottom container and with the front shell of the top container, that is operatable through a front locking knob, and di un rear locking device interacting with the rear shell of the bottom container and with the rear shell of the top container, that is operatable through a rear locking knob, wherein the front and rear knobs are substantially circular and are arranged externally to the front shell and the rear shell, respectively, of the bottom container, and they are provided with a central cylindrical pin crossing the front shell and the rear shell, respectively, of the bottom container, wherein the central cylindrical pin is configured to insert into one of the central circular recesses and interacts with a spring that is configured to force the central cylindrical pin in direction of insertion into one of the central circular recesses, each one of said front and rear knobs being configured to assume a release position, corresponding to the release configuration, at which it is spaced from the front or rear shell, respectively, of the bottom container and at which the central cylindrical pin is extracted from the central circular recesses, and a lock position, corresponding to the lock configuration, at which the front and rear shell are pushed against the front and rear shells, respectively, of the bottom container, and at which the respective central cylindrical pins are inserted into one of the central circular recesses of the front and rear shells, respectively, of the bottom container.

According to an additional aspect of the invention, the number of said at least two geometric configurations which the expandable trolley suitcase is configured to assume is equal to four, thereby the number of said two or more front linear grooves and of said two or more rear linear grooves is ranging from four to six.

According to another aspect of the invention, the number of said two or more front linear grooves and of said two or more rear linear grooves is equal to five or six.

According to a further aspect of the invention, an inner surface of each one of the front and rear shells of the bottom container may be provided with two protruding linear buffer sealing elements, optionally made of rubber, more optionally implemented through convex rubber seals, arranged along the extraction direction, which are configured to at least partially insert into two respective front and rear linear grooves, respectively, and to maintain a seal between the bottom container and the top container, wherein a distance between each protruding linear buffer sealing element and the central cylindrical pin of each one of the front and rear shells of the bottom container is equal to the distance separating two front or rear linear grooves adjacent to each other, thereby, when the central cylindrical pin is inserted into one of the central circular recesses of a respective front or rear linear grooves, the two protruding linear buffer sealing elements are inserted into at least one of said two or more front or rear linear grooves adjacent to that into the central circular recess of which the central cylindrical pin is inserted.

According to an additional aspect of the invention, the bottom container and the top container may be made of plastic material, optionally acrylonitrile-butadiene-styrene (also known as ABS).

According to another aspect of the invention, a bottom wall of the bottom container may be externally provided with two or more rotating elements.

According to a further aspect of the invention, said two or more rotating elements may be selected from the group comprising fixed axle wheels, swivel wheels, fixed axle rollers and swivel rollers.

According to an additional aspect of the invention, a pull-out handle is mounted on a rear wall of the bottom container and/or wherein a fixed top handle is mounted on una top wall of the top container.

The expandable trolley suitcase according to the invention offers numerous advantages.

In fact, it is configured to change its dimensions, i.e. the storage volume (of the internal space), according to the user's needs and/or the stowage requirements, e.g. imposed by airlines for cabin baggage.

In this way, the user can purchase one single expandable trolley suitcase instead of a plurality of trolley suitcases of different sizes which could be no longer used following an unexpected change in the stowage conditions related to the dimensions of the trolley suitcase, that could also entail additional costs for the transport thereof, such as to make its use inconvenient, if not impossible.

The present invention will be now described, by way of illustration and not by way of limitation, according to its preferred embodiments, by particularly referring to the Figures of the annexed drawings, in which:

FIG. 1 shows a rear elevation perspective view of the preferred embodiment of the expandable trolley suitcase according to the invention (where an indication EJECT is shown that is not part of the patent protection of the present invention);

FIG. 2 shows front elevation perspective view of the expandable trolley suitcase of FIG. 1 when it assumes four geometric configurations;

FIG. 3 shows a front view of the expandable trolley suitcase of FIG. 1;

FIG. 4 shows a right side view of the expandable trolley suitcase of FIG. 1;

FIG. 5 shows a top plan view of the expandable trolley suitcase of FIG. 1;

FIG. 6 shows a rear view of the expandable trolley suitcase of FIG. 1;

FIG. 7 shows the plan view of FIG. 5 (FIG. 7a ) and two partial sectional views along the plane AA (FIG. 7b ) and along the plane BB (FIG. 7c ) thereof;

FIG. 8 shows the plan view of FIG. 5 (FIG. 8a ) and two partial sectional views along the plane BB (FIG. 8b ) and along the plane CC (FIG. 8c ) thereof;

FIG. 9 shows the front view of FIG. 3 (FIG. 9a ), a sectional view along the plane DD thereof (FIG. 9b ) and a related enlarged portion (FIG. 9c );

FIG. 10 shows the partial sectional view along the plane BB (FIG. 10a ) and a partial sectional view along the plane piano CC (FIG. 10b ) of the plan view of FIG. 8a ; and

FIG. 11 schematically shows a mode of operation of some components of the trolley suitcase of FIG. 1.

In the Figures identical reference numerals will be used for alike elements. Moreover, although the specific dimensions of the preferred embodiment of the expandable trolley suitcase according to the invention are shown in the Figures, it must be noted that these dimensions are not essential features of the invention and in other embodiments of the expandable trolley suitcase they can be modified at least in part with respect to those of the preferred embodiment, still remaining within the scope of protection as defined by the attached claims.

With reference to FIGS. 1 and 2, it may be observed a preferred embodiment of the expandable trolley suitcase having an internal storage space. The bottom wall of the expandable trolley suitcase is conventionally provided with four swivel wheels (rotating around an axis orthogonal to the bottom wall), indicated with the reference numeral 190. Moreover, the expandable trolley suitcase is provided with a pull-out handle 180, namely conventionally telescopically extractable by means of two telescopic rods (indicated with the reference 500 in FIGS. 2 and 9 b, mounted on a rear wall 120 of the expandable trolley suitcase and of a fixed top handle 280 mounted on a top wall 230 of the expandable trolley suitcase .

It must be noted that other embodiments of the expandable trolley suitcase according to the invention can have rotating elements even different from swivel wheels, such as for instance fixed axle wheels or fixed axle rollers or swivel rollers (rotating around an axis orthogonal to the wall bottom), and/or a number of rotating elements different from four, for instance two rotating elements, and/or it can be devoid of the fixed top handle 280 and/or one or more additional handles positioned on at least one of the side walls of the expandable trolley suitcase, still remaining within the scope of protection as defined by the attached claims.

The expandable trolley suitcase comprises a bottom container 100, having a top opening, and a top container 200, having a bottom opening, which are slidably coupled to each other in correspondence of the bottom opening of the first one and of the top opening of the second one (and thus the internal space of the bottom container 100 is in communication with the internal space of the top container 200), whereby the expandable trolley suitcase is configured to assume four geometric configurations defining four respective storage volumes delimited by the bottom container 100 and top container 200. In particular, the top container 200 is configured to slide inside the bottom container 100 and the expandable trolley suitcase is configured to assume one of the geometric configurations shown in FIG. 2, namely: a minimum geometric configuration (shown in FIG. 2a ) having a minimum storage volume; a first intermediate geometric configuration (shown in FIG. 2b ) having a first intermediate storage volume, greater than the minimum storage volume; a second intermediate geometric configuration (shown in FIG. 2c ) having a second intermediate storage volume, greater than the first intermediate storage volume; and a maximum geometric configuration (shown in FIG. 2d ) having a maximum storage volume greater than the second intermediate storage volume.

When the swivel wheels 190 rest on a floor, the height of the expandable trolley suitcase with respect to the latter in the four geometric configurations is 45 cm, 50 cm, 55 cm and 60 cm; in each one of the four geometric configurations the expandable trolley suitcase has a width of 40 cm and a depth of 20 cm. However, it is reiterated that the specific dimensions of the expandable trolley suitcase according to the invention are not essential features of the invention.

The bottom wall of the bottom container 100 acts as bottom wall of the expandable trolley suitcase and the top wall 230 of the top container 200 operates as top wall of the expandable trolley suitcase. The pull-out handle 180 is mounted on the rear wall 120 of the bottom container 100, which forms along with the rear wall 220 of the top container 200 the rear wall of the expandable trolley suitcase.

The expandable trolley suitcase further comprises a front locking device, interacting with the front wall 110 of the bottom container 100 and with the front wall 210 of the top container 200, that is operatable through a front locking knob 300, and a rear locking device, interacting with the rear wall 120 of the bottom container 100 and with the rear wall 220 of the top container 200, that is operatable through a rear locking knob 350. The front and rear locking knobs 300 and 350 are each configured to assume a release configuration, at which it allows a reciprocal sliding of the top container 200 and bottom container 100, and a lock configuration, at which it prevents the reciprocal sliding of the top container 200 and bottom container 100 and locks the expandable trolley suitcase in one of its four geometric configurations shown, in particular, in FIG. 2.

In particular, starting from the minimum geometric configuration of FIG. 2a , when the swivel wheels 190 rest on a floor, thereby the bottom wall of the bottom container 100 is supported by the floor by means of the swivel wheels 190, when the pull-out handle 180 is extracted in a direction (indicated in FIGS. 2b, 2c and 2d by arrows A) of extraction, whereby it moves away from the bottom wall of the bottom container 100, and when the front and rear locking knobs 300 and 350 assume the release configuration, the top container 200 can be slid inside the bottom container 100 in the extraction direction A to cause the expandable trolley suitcase to assume one of the other three geometric configurations shown in FIGS. 2b, 2c and 2d , at which it can be locked by making the front and rear locking knobs 300 and 350 assume the lock configuration.

Also referring to FIGS. 3 to 10, it can be observed that the bottom container 100 comprises a front shell 100F and a rear shell 100R, each one made of a rigid material and having a bottom edge and two lateral edges, which are hinged to each other (through a hinge 150 shown in FIGS. 1 and 9 b) on a first lateral edge, and which are closable by a zipper 160 running along the bottom edge and the second lateral edge in a conventional way. Similarly, the top container 200 comprises a front shell 200F and a rear shell 200R, each one made of a rigid material and having a bottom edge and two lateral edges, which are closable by a zipper 260 running along the bottom edge and lateral edges in a conventional way. In particular, FIG. 10b schematically shows the opening path C1 of the zipper 160 and the opening path C2 of the zipper 260.

Four linear telescopic guides with aluminium balls allow the top container 200 to slide inside the bottom container 100. In particular, as shown in FIGS. 7c, 8b, 9b, 9c and 10a , two front telescopic guides 400F are each coupled to the two front shells 100F and 200F and two rear telescopic guides 400R are each coupled to the two rear shells 100R and 200R. The seal between the top container 200 and the bottom container 100 is conventionally ensured by gaskets 450F, 450R, 455F and 455R (shown in FIGS. 7b and 8c ) interposed between the front shells 100F and 200F and between the rear shells 100R and 200R .

The front shell 200F of the top container 200 is provided with five front linear grooves 271F, 272F, 273F, 274F and 275F; likewise, the rear shell 200R of the top container 200 is provided with five rear linear grooves 271R, 272R, 273R, 274R and 275R. When the top container 200 is slidably coupled to the bottom container 100, the five front linear grooves 271F-275F and the five rear linear grooves 271R-275R, optionally concave ones, are oriented in direction orthogonal to the extraction direction A (thereby, when the swivel wheels 190 rest on a floor, the front and rear linear grooves are parallel to the floor itself), and the five front linear grooves 271F-275F are each at a respective height from the floor identical to the height from the floor of a corresponding one of the five rear linear grooves 271R-275R, thereby the five front linear grooves 271F-275F face the five rear linear grooves 271R-275R. Each groove is provided with a central circular recess (indicated with reference numerals 281F-285F for the front linear grooves and with reference numerals 281R-285R for the rear linear grooves).

The front and rear knobs 300 and 350 are substantially circular and are arranged externally to the front shell 100F and rear shell 100R of the bottom container 100, and they are provided with a central cylindrical pin 310 crossing the front shell 100F and the rear shell 100R, respectively, of the bottom container 100. The central cylindrical pin 310 is configured to insert into one of the central circular recesses 281F-285F and 281R-285R, respectively. Each central cylindrical pin 310 interacts with a respective spring 315 that is configured to force the central cylindrical pin 310 in the direction going from the bottom container 100 to the top container 200, i.e. in the direction of insertion into one of the central circular recesses. Moreover, the inner surface of the front shell 100F and rear shell 100R, respectively, of the bottom container 100 is provided with two protruding linear buffer sealing elements 320, optionally made of rubber, more optionally implemented through convex rubber seals, arranged along the extraction direction A, which are configured to partially insert into two respective front or rear linear grooves 271F-275F or rear 271R-275R. The two protruding linear buffer sealing elements 320 contribute to the seal between the top container 200 and the bottom container 100.

In particular, the distance between each protruding linear buffer sealing element 320 and the central cylindrical pin 310 is equal to the distance separating two front or rear linear grooves adjacent to each other, whereby when the central cylindrical pin 310 is inserted into one of the central circular recesses 281F-285F and 281R-285R of a respective front or rear linear groove, respectively, the two protruding linear buffer sealing elements 320 are inserted into the two front or rear linear grooves adjacent to the one into the central circular recess 281F-285F or 281R-285R of which the central cylindrical pin 310 is inserted, as shown in particular in FIGS. 7c, 8b and 10a . In this case, the respective spring 315 maintains the respective front or rear knob 300 or 350 forced onto the wall of the front or rear shell 100F or 100R of the bottom container 100 and further maintains the pin 310 inside the central circular recess into which it is inserted, preventing the top container 200 from sliding with respect to the bottom container 100, thereby the respective locking device assumes the lock configuration. By pulling the front or rear knob 300 or 350, i.e. by pressing the respective spring 315, the front or rear knob 300 or 350 separates (i.e. moves away) from the wall of the front or rear shell 100F or 100R of the bottom container 100 and the respective central cylindrical pin 310 is extracted from the central circular recess into which it is inserted, thereby the respective locking device assumes the release configuration; subsequently, by rotating the knob, the base of the knob is caused to interact with one or more protruding elements which protrude from the front or rear shell 100F or 100R of the bottom container 100 by maintaining the front or rear knob 300 or 350 spaced from the wall of the front or rear shell 100F or 100R of the bottom container 100 and thus preventing the front or rear knob 300 or 350 from returning to push on the wall of the front or rear shell 100F or 100R of the bottom container 100 and further preventing the respective central cylindrical pin 310 from inserting again into the central circular recess from which it has been extracted, thus stably maintaining the locking device in the release configuration.

As stated above, when both locking devices assume the release configuration, the top container 200 can slide inside the bottom container 100 and the expandable trolley suitcase can assume any one of its four geometric configurations shown in FIG. 2, at which it can be locked by rotating the front and rear knobs 300 and 350 backwards thus interrupting the interaction of the knob base with said one or more projecting elements which protrude from the front or rear shell 100F or 100R of the bottom container 100, causing the front or rear knob 300 or 350 to return to push on the wall of the front or rear shell 100F or 100R of the bottom container 100 and causing the central cylindrical pins 310 to insert into the central circular recesses of the front and rear linear groove corresponding to the geometric configuration under consideration, whereby the locking devices assume again the lock configuration; in this case, the protruding linear buffer sealing elements 320 are inserted into two front and rear linear grooves corresponding to the geometric configuration under consideration and, during the extraction of the top container 200, they transmit a snap movement to the top container 200 as soon as they insert into these two front and rear linear grooves.

It must be noted that, when the expandable trolley suitcase assumes the maximum geometric configuration (shown in FIG. 2d ), the protruding linear buffer sealing element 320 that is located below the central cylindrical pin 310 (when the swivel wheels 190 rest on a floor) is not inserted in any linear groove, but it is located below the front shell 200F or the rear shell 200R of the top container 200, optionally acting as a support for the front shell 200F or rear shell 200R of the top container 200. In an alternative embodiment of the expandable trolley suitcase according to the invention, the front shell 200F of the top container 200 can be provided with six front linear grooves and the rear shell 200R of the top container 200 can be provided with six rear linear grooves, whereby even when the expandable trolley suitcase assumes the maximum geometric configuration (shown in FIG. 2d ), both the protruding linear buffer sealing elements 320 of the inner surface of the front shell 100F and rear shell 100R, respectively, of the bottom container 100 are inserted into the two front and rear linear grooves adjacent to the penultimate front and rear linear groove, respectively, considered from the top to the bottom of the front shell 200F and rear shell 200R of the top container 200, respectively, into the central circular recess of which the central cylindrical pin 310 of the front knob 300 and rear knob 350, respectively, is inserted. In a different alternative embodiment of the expandable trolley suitcase according to the invention, the front shell 200F of the top container 200 can be provided with four front linear grooves and the rear shell 200R of the top container 200 can be provided with four rear linear grooves, whereby even when the expandable trolley suitcase assumes one of the four geometric configurations (shown in FIG. 2), the two linear protruding buffer sealing elements 320 (which are optional) of the inner surface of the front shell 100F and rear shell 100R, respectively, of the bottom container 100 are arranged at the same height as the central cylindrical pin 310 of the front knob 300 and rear knob 350, respectively (and consequently at the same distance from the bottom wall of the front shell 100F and rear shell 100R, respectively, of the bottom container 100), and at the sides of the central cylindrical pin 310 of the front knob 300 and rear knob 350, respectively, so as to be configured to insert into the same front and rear linear groove, respectively, into the central circular recess of which the central cylindrical pin 310 of the front knob 300 and rear knob 350, respectively, is inserted.

In particular, in the lock configuration, the front and rear knobs 300 and 350 are resting on the front shell 100F and rear shell 100R of the bottom container 100, respectively, whereby, in case of fall of the expandable trolley suitcase, these knobs remain in the lock configuration preventing accidental uncoupling of the top container 200 from the bottom container 100 and the opening of the expandable trolley suitcase.

In particular, in the lock configuration, the front and rear knobs 300 and 350 are resting on the front shell 100F and rear shell 100R of the bottom container 100, respectively, whereby, in case of fall of the expandable trolley suitcase, these knobs remain in the lock configuration preventing accidental uncoupling of the top container 200 from the bottom container 100 and the opening of the expandable trolley suitcase.

The front and rear shells 100F and 100R of the bottom container 100 and the shells 200F and 200R of the top container 200 are made of plastic material, optionally acrylonitrile-butadiene-styrene (also known as ABS), a material that guarantees rigidity and flexibility, strength to scratches, lightness and ease in recycling at the end of life.

Thanks to the fact that the zippers 160 and 260 are independent of each other, the zipper 260 of the top container 200 can come out of the bottom container 100 making the closure system reliable and efficient for any geometric configuration assumed by the expandable trolley suitcase. To compensate for the misalignment of the two zippers 160 and 260, the slider 262 of the zipper 260 of the top container 200 has a greater length than the slider 162 of the zipper 160 of the bottom container 100, causing, when the zippers 160 and 260 are both closed, the holes of the two sliders 162 and 262 to be configured to be perfectly aligned and to allow their closure with a padlock 600, as shown in FIG. 11.

Optionally, the bottom and top containers 100 and 200 can be made with different colours in order to create various colour combinations and to highlight the possibility of increasing the storage volume of the expandable trolley suitcase. To this end, stylised arrows indicating the direction of movement of the bottom and top containers 100 and 200 can be embossed on the bottom and top containers 100 and 200 to obtain an increase in the storage volume of the expandable trolley suitcase.

It must be noted that other embodiments of the expandable trolley suitcase according to the invention can have locking devices, interacting with the bottom container and the top container, also different from those illustrated for the preferred embodiment, and/or a number of locking devices different from two, e.g. one or more than two. In particular, some embodiments of the expandable trolley suitcase according to the invention may have locking devices which allow the expandable trolley suitcase to be stably locked in any geometric configuration ranging from the minimum geometric configuration to the maximum geometric configuration, thus modifying continuously the storage volume of the expandable trolley suitcase.

It must be also noted that further embodiments of the expandable trolley suitcase according to the invention may have a different number of geometric configurations, e.g. two, three or more than four; in this case, if the locking devices are those illustrated for the preferred embodiment, the linear grooves on the top container which interact with the respective knob can be less than or greater than five. In particular, in the case where there are two geometric configurations, the linear grooves on the top container which interact with the respective knob can be from two to four; in the case where the geometric configurations are three, the linear grooves on the top container which interact with the respective knob can be from three to five; in the case where the geometric configurations are five, the linear grooves on the top container which interact with the respective knob can be from five to seven; and so on.

It must be still noted that further embodiments of the expandable trolley suitcase according to the invention may have the bottom container 100 which slides inside the top container 200, still remaining within the scope of protection as defined by the attached claims.

The preferred embodiments of this invention have been described and a number of variations have been suggested hereinbefore, but it should be understood that those skilled in the art can make other variations and changes without so departing from the scope of protection thereof, as defined by the attached claims. 

1. Expandable trolley suitcase comprising a bottom container having a top opening, and a top container having a bottom opening, the top container and the bottom container being slidably coupled to each other in correspondence of the bottom opening of the first one and of the top opening of the second one, at least one locking device interacting with the bottom container and with the top container and configured to assume a release configuration, at which it allows a reciprocal sliding of the bottom container and top container, and a lock configuration, at which it prevents the reciprocal sliding of the bottom container and top container, thereby the expandable trolley suitcase is configured to assume at least two geometric configurations, at which said at least one locking device assumes the lock configuration, depending on a position assumed by one between the bottom container and the top container with respect to the other, each one of said at least two geometric configurations having a respective storage volume delimited by the bottom container and top container, said at least two geometric configurations including a minimum geometric configuration having a minimum storage volume and a maximum geometric configuration having a maximum storage volume.
 2. Expandable trolley suitcase according to claim 1, wherein the top container and the bottom container are slidably coupled to each other through a plurality of linear telescopic guides.
 3. Expandable trolley suitcase according to claim 2, wherein said plurality of linear telescopic guides comprises four linear telescopic guides.
 4. Expandable trolley suitcase according to claim 1, wherein the top container is configured to slide inside the bottom container.
 5. Expandable trolley suitcase according to claim 4, wherein the bottom container comprises a front shell and a rear shell, each one made of a rigid material and having a bottom edge and two lateral edges, which are hinged to each other on a first lateral edge and which are closable by a zipper running along the bottom edge and the second lateral edge of the shells of the bottom container, and the top container comprises a front shell and a rear shell, each one made of a rigid material and having a bottom edge and two lateral edges, which are closable by a zipper running along the bottom edge and the lateral edges of the shells of the top container.
 6. Expandable trolley suitcase according to claim 5, comprising one or more sealing gaskets interposed between the front shells and between the rear shells which are configured to maintain a seal between the bottom container and the top container.
 7. Expandable trolley suitcase according to claim 5, wherein the front shell of the top container is provided with two or more front linear grooves, the number of which is ranging from the number of said at least two geometric configurations to the number of said at least two geometric configurations increased by two, facing corresponding two or more rear linear grooves, the number of which is equal to the number of said two or more front linear grooves, with which the rear shell of the top container provided, wherein said two or more front linear grooves and said two or more rear linear grooves are oriented in direction orthogonal to a direction of extraction of the top container from the bottom container, each one of said two or more front linear grooves and of said two or more rear linear grooves having a respective central circular recess, wherein said at least one locking device consists of comprises a front locking device interacting with the front shell of the bottom container and with the front shell of the top container, that is operatable through a front locking knob, and di un rear locking device interacting with the rear shell of the bottom container and with the rear shell of the top container that is operatable through a rear locking knob, wherein the front and rear knobs are substantially circular and are arranged externally to the front shell and the rear shell, respectively, of the bottom container, and they are provided with a central cylindrical pin crossing the front shell and the rear shell, respectively, of the bottom container, wherein the central cylindrical pin is configured to insert into one of the central circular recesses and interacts with a spring that is configured to force the central cylindrical pin in direction of insertion into one of the central circular recesses, each one of said front and rear knobs being configured to assume a release position, corresponding to the release configuration, at which it is spaced from the front or rear shell, respectively, of the bottom container and at which the central cylindrical pin is extracted from the central circular recesses, and a lock position, corresponding to the lock configuration, at which the front and rear shell are pushed against the front and rear shells, respectively, of the bottom container and at which the respective central cylindrical pins are inserted into one of the central circular recesses of the front and rear shells, respectively, of the bottom container.
 8. Expandable trolley suitcase according to claim 7, wherein the number of said at least two geometric configurations which the expandable trolley suitcase is configured to assume is equal to four, thereby the number of said two or more front linear grooves and of said two or more rear linear grooves is ranging from four to six.
 9. Expandable trolley suitcase according to claim 8, wherein the number of said two or more front linear grooves and of said two or more rear linear grooves is equal to five or six.
 10. Expandable trolley suitcase according to claim 9, wherein an inner surface of each one of the front and rear shells of the bottom container is provided with two protruding linear buffer sealing elements, arranged along the extraction direction, which are configured to at least partially insert into two respective front and rear linear grooves, respectively, and to maintain a seal between the bottom container and the top container, wherein a distance between each protruding linear buffer sealing element and the central cylindrical pin of each one of the front and rear shells of the bottom container is equal to the distance separating two front or rear linear grooves adjacent to each other, thereby, when the central cylindrical pin is inserted into one of the central circular recesses of a respective front or rear linear grooves, the two protruding linear buffer sealing elements are inserted into at least one of said two or more front or rear linear grooves adjacent to that into the central circular recess of which the central cylindrical pin is inserted.
 11. Expandable trolley suitcase according to claim 1, wherein the bottom container and the top container are made of plastic material.
 12. Expandable trolley suitcase according to claim 1, wherein a bottom wall of the bottom container is externally provided with two or more rotating elements.
 13. Expandable trolley suitcase according to claim 12, in which said two or more rotating elements are selected from the group comprising fixed axle wheels, swivel wheels, fixed axle rollers and swivel rollers.
 14. Expandable trolley suitcase according to claim 1, wherein a pull-out handle is mounted on a rear wall of the bottom container and/or wherein a fixed top handle is mounted on una top wall of the top container.
 15. Expandable trolley suitcase according to claim 2, wherein said linear telescopic guides comprises linear telescopic guides with aluminium balls.
 16. Expandable trolley suitcase according to claim 10, said two protruding linear buffer sealing elements are made of rubber.
 17. Expandable trolley suitcase according to claim 16, said two protruding linear buffer sealing elements are implemented through convex rubber seals.
 18. Expandable trolley suitcase according to claim 11, wherein the bottom container and the top container are made of acrylonitrile-butadiene-styrene (also known as ABS). 